U.S. patent number 7,608,056 [Application Number 11/588,806] was granted by the patent office on 2009-10-27 for steerable catheter devices and methods of articulating catheter devices.
This patent grant is currently assigned to Wilson-Cook Medical Inc.. Invention is credited to Kenneth C. Kennedy, II.
United States Patent |
7,608,056 |
Kennedy, II |
October 27, 2009 |
Steerable catheter devices and methods of articulating catheter
devices
Abstract
Steerable catheter devices are provided having a proximal first
end portion, an elongate intermediate portion, and a distal
flexible second end portion defining a longitudinal axis, and at
least one channel having a proximal opening and terminating at an
occluded distal end radially offset relative to the central
longitudinal axis and positioned within the catheter flexible
second end portion substantially straight in a relaxed position and
bent when the occluded distal end is under a change in internal
fluid pressure. Optionally, the catheter further has a dye
injection lumen and a tool receiving passageway extending from the
first end portion to the second end portion. The occluded distal
end is axially elastically distensible under an internal fluid
pressure to deflect (thereby to steer) the catheter second end
portion through the tortuous path of a vessel passageway when used
percutaneously or working channel of an endoscope or endoscope
accessory device.
Inventors: |
Kennedy, II; Kenneth C.
(Clemmons, NC) |
Assignee: |
Wilson-Cook Medical Inc.
(Winston-Salem, NC)
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Family
ID: |
37714413 |
Appl.
No.: |
11/588,806 |
Filed: |
October 27, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070100235 A1 |
May 3, 2007 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60731763 |
Oct 31, 2005 |
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Current U.S.
Class: |
604/95.03;
604/525; 604/527 |
Current CPC
Class: |
A61B
6/504 (20130101); A61M 25/0155 (20130101); A61M
25/0105 (20130101); A61M 25/0136 (20130101); A61M
25/0141 (20130101); A61B 1/0051 (20130101); A61B
6/481 (20130101); A61B 2017/003 (20130101) |
Current International
Class: |
A61M
31/00 (20060101); A61M 37/00 (20060101) |
Field of
Search: |
;604/95.03,96.01,97.01,98.01,102.03,524-528,530,532,536,95.01,95.02,95.04,523 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Written Opinion, dated Jan. 10, 2008, for International Application
No. PCT/US2006/042490. cited by other .
Search Report and Written Opinion dated Mar. 1, 2007, for
International Application No. PCT/US2006/042490. cited by
other.
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Primary Examiner: Lucchesi; Nicholas D
Assistant Examiner: Price; Nathan R
Attorney, Agent or Firm: Brinks Hofer Gilson & Lione
Parent Case Text
RELATED APPLICATIONS
The present patent document claims the benefit of the filing date
under 35 U.S.C. .sctn.119(e) of U.S. Provisional Patent Application
filed on Oct. 31, 2005 entitled, "Steerable Catheter Devices and
Methods of Articulating Catheter Devices," and having an
application Ser. No. 60/731,763, the disclosure of which is hereby
incorporated by reference in its entirety.
Claims
What is claimed is:
1. A steerable catheter assembly comprising: a catheter having an
elongated intermediate portion extending between a proximal first
end portion and a distal flexible second end portion, a flexible
steerable distal tip portion extending distally from the distal
second end portion and an expansion resistant distally tapering
portion there between, the flexible steerable distal tip having a
substantially solid central core section, the first and second end
portions defining a central longitudinal axis extending through the
core section, the flexible second end portion having a first outer
diameter and the flexible steerable distal tip portion having a
second outer diameter that is smaller than the first outer
diameter; an elongate chamber body having a proximal opening
located at or near the catheter first end portion and terminating
at an elastically fluid-distensible occluded distal end formed
integral within the flexible steerable distal tip portion, the
elongate chamber body proximal opening and elongate chamber body
distensible occluded distal end defining a longitudinal fluid flow
channel that extends longitudinally between and in communication
with the elongate chamber body proximal opening and the elongate
chamber body occluded distal end, the longitudinal fluid flow
channel being configured to transmit fluid to the elastically
fluid-distensible occluded distal end of the elongate chamber body,
the elastically fluid-distensible occluded distal end being
radially offset and substantially parallel to the catheter central
longitudinal axis, the elastically fluid-distensible occluded
distal end is configured to distend from a neutral position to a
lengthened bending position; and a fluid flow actuator operatively
coupled at or near the catheter first end portion in communication
with the proximal opening of the elongate chamber body, the fluid
flow actuator configured to control fluid supply to the elongate
chamber body occluded distal end, wherein the central core section
is configured to inhibit radial inward expansion of the elastically
fluid-distensible occluded distal end when the fluid flow actuator
supplies fluid thereto, wherein the elongate chamber body occluded
distal end is configured to elastically distend axially under a
change in internal fluid pressure without substantially changing
the catheter flexible steering tip portion outer diameter and
thereby configured to articulate the catheter flexible steering tip
portion from a substantially straight relaxed position to a bending
position in response to a change of fluid pressure.
2. The device of claim 1 further comprising a radial expansion
resistant outer reinforcement positioned circumferentially about
the flexible steerable distal tip portion and configured to allow
axial distension of the elastically fluid-distensible occluded
distal end without substantial outward radial expansion of the
occluded distal end.
3. The device of claim 2 wherein the radial expansion resistant
outer reinforcement is selected from the group consisting of a
coil, spring, wire, fiber, mesh, increased durometric material
relative to the chamber body occluded distal end, anisotropic
material, and a slotted cannula.
4. The device of claim 1 further comprising a dye injection lumen
comprising a proximal opening located at or near the proximal first
end portion of the catheter and a distal end opening located at or
near the flexible steerable distal tip portion of the catheter.
5. The device of claim 1 further comprising a tool receiving
passageway disposed within the catheter and extending from a first
opening at or near the proximal first end portion of the catheter
and a second opening at the distal flexible second end portion, the
passageway being substantially coaxial with the central
longitudinal axis at the proximal first end portion of the
catheter.
6. The device of claim 1 wherein elastically fluid-distensible
occluded distal end comprises a substantially circular cross
section in the neutral position.
7. The device of claim 1 wherein elastically fluid-distensible
occluded distal end comprises a substantially non-uniform cross
section in the neutral position.
8. The device of claim 1 wherein the flexible steerable distal tip
portion of the catheter comprises an anisotropic material that is
more compliant in the axial direction than it is in the transverse
direction.
9. The device of claim 1 wherein the fluid actuator further
comprises an actuation mechanism selected from the group consisting
of mechanically operated elements, electronically operated
elements, electromechanically operated elements, pneumatically
operated elements, hydraulically operated elements,
piezoelectrically operated elements, thermomechanically,
chemomechanically operated elements, and photoelectrically operated
elements.
10. The device of claim 1 further comprising a second elongate
chamber body terminating at a second elastically fluid-distensible
occluded distal end positioned within the flexible steerable distal
tip portion.
11. The device of claim 10 wherein the second elongate chamber body
comprises a second proximal opening located at or near the catheter
first end portion, the second elastically fluid-distensible
occluded distal end formed integral within the flexible steerable
distal tip portion and radially offset and substantially parallel
to the catheter central longitudinal axis and non-axial to the
first elastically fluid-distensible occluded distal end such that
the catheter central longitudinal axis of the core section of the
catheter flexible steerable distal tip portion is positioned
between the first and second elastically fluid-distensible occluded
distal ends, the second elastically fluid-distensible occluded
distal end being configured to distend from the neutral position to
a second lengthened bending position.
12. The device of claim 11 wherein the fluid flow actuator is
operatively coupled at or near the catheter first end portion in
communication with at least the first and second elongate chamber
body proximal openings, the fluid flow actuator configured to
control fluid supply to at least the first and second fluid flow
channels and corresponding first and second elongate chamber body
occluded distal ends.
13. The device of claim 11 further comprising third elongate
chamber body having a third proximal opening located at or near the
catheter first end portion and terminating at a third elastically
fluid-distensible occluded distal end positioned within the
flexible steerable distal tip portion, the third elongate chamber
body proximal opening and third elongate chamber body distensible
occluded distal end defining a third longitudinal fluid flow
channel that extends longitudinally between and in communication
with the third elongate chamber body proximal opening and the third
elongate chamber body occluded distal end, the third longitudinal
fluid flow channel chamber being configured to transmit fluid to
the third elastically fluid-distensible occluded distal end of the
elongate chamber body, the third elastically fluid-distensible
occluded distal end formed integral within the flexible steerable
distal tip portion and being radially offset and substantially
parallel relative to the catheter central longitudinal axis of the
core section such that the first, second, and third elastically
fluid-distensible occluded distal ends are non-axial.
14. The device of claim 13 further comprising a fourth elongate
chamber body having a fourth proximal opening located at or near
the catheter first end portion and terminating at a fourth
elastically fluid-distensible occluded distal end positioned within
the flexible steerable distal tip portion, the fourth elongate
chamber body proximal opening and fourth elongate chamber body
distensible occluded distal end defining a fourth longitudinal
fluid flow channel that extends longitudinally between and in
communication with the fourth elongate chamber body proximal
opening and the fourth elongate chamber body occluded distal end,
the fourth longitudinal fluid flow channel chamber being configured
to transmit fluid to the fourth elastically fluid-distensible
occluded distal end of the elongate chamber body, the fourth
elastically fluid-distensible occluded distal end formed integral
within the flexible steerable distal tip portion and being radially
offset and substantially parallel relative to the catheter central
longitudinal axis of the core section such that the first, second,
third, and fourth elastically fluid-distensible occluded distal
ends are non-axial.
15. The device of claim 13 wherein the fluid flow actuator is
operatively coupled at or near the catheter first end portion in
communication with at least two of the first, second, and third
elongate chamber body proximal openings, the fluid flow actuator
configured to control fluid supply to at least two of the first,
second, and third fluid flow channels and corresponding first,
second, and third elongate chamber body occluded distal ends.
16. The device of claim 14 wherein the fluid flow actuator is
operatively coupled at or near the catheter first end portion in
communication with at least two of the first, second, third, and
fourth elongate chamber body proximal openings, the fluid flow
actuator configured to control fluid supply to at least two of the
first, second, third, and fourth fluid flow channels and
corresponding first, second, third, and fourth elongate chamber
body occluded distal ends.
Description
FIELD OF THE INVENTION
The present invention relates to catheter devices for use with
endoscopes or percutaneously with vascular medical devices and the
like, wherein the catheters employ fluids used to steer the distal
tip of the catheter.
BACKGROUND OF THE INVENTION
Physicians and other healthcare professionals (collectively,
"physician") commonly use catheters in a variety of medical
procedures. Catheters guide and introduce a variety of medical
devices, guide wires, drug delivery tools, therapeutic agents
(e.g., drugs, medication, narcotics, antibiotics, pharmaceutical
products, and/or medicinal agents, therapies, or substances) and
other operative instruments or devices (individually and
collectively, "instruments") into the body percutaneously or
through a working channel of an endoscope or accessory channel to
be used with an endoscope. Thus, catheters often serve as a
highway--a temporarily established path--for placing, introducing,
exchanging, and replacing instruments during a medical procedure,
thereby eliminating the need for performing delicate navigation
procedures for each instrument passed into a vessel passageway.
A vessel passageway includes any lumen, chamber, channel, opening,
bore, orifice, flow passage, duct, organ, or cavity for the
conveyance, regulation, flow, or movement of bodily fluids and/or
gases of an animal. For example, physicians frequently use
catheters in medical procedures that involve the passageways of a
heart, blood vessel, artery, vein, capillary, bronchiole, brachial,
trachea, esophagus, aorta, intestine, bile duct, pancreas, liver,
gall bladder, ureter, urethra, fallopian tube, and other locations
in a body (collectively, "vessel") to name a few. Similarly,
physicians may place catheters through a working channel of an
endoscope, or a channel endoscope accessory device, during
endoscopic medical procedures that involve these vessel
passageways.
In order to negotiate a typically tortuous path of a vessel
passageway or to avoid obstacles during insertion of a catheter
through vessel passageways, conventional catheters include hollow
flexible tubes with a tactile first end and a flexible second end.
The first end forms the end that physicians sometimes grip or
otherwise secure, and the second end forms the end that physicians
position at or near the target site. The hollow tube normally
comprises a substantially circular cross section to mimic the
configuration of a typical vessel passageway or the channel of an
endoscope or endoscope accessory device.
Maneuvering the catheter second end through the vessel passageway
and to the target site often presents a time-consuming endeavor for
the physician. In order to obtain a desired maneuverability of the
second end, conventional catheters commonly employ one of several
approaches and features.
In one type of catheter, the second end moves substantially
passively. As the physician inserts the catheter through the vessel
passageway, the catheter follows the path of the vessel passageway.
Should this catheter enter the wrong vessel opening, such as in a
case of a bifurcated vessel pathway, the physician must engage in a
series of steps of manually withdrawing the second end from the
wrong vessel opening, and then reinserting the second end until it
enters the desired opening. In order to accomplish this feat, the
physician may also rotate the catheter about the catheter
longitudinal axis. A physician may need to make numerous attempts
with the passive catheter to gain access through the desired
opening. Any of these steps increases the length of time for the
medical procedure and possibly patient discomfort.
The present inventions solve these and other problems with a
steerable distal second end portion and/or sterrable distal
tip.
In another type of catheter, the catheter second end may include a
slight pre-formed bend. Thus, the catheter second end follows
closer to the wall of the vessel passageway than it does the center
of the vessel passageway. Upon encountering a choice of taking two
or more vessel openings (again using a bifurcated vessel pathway as
an example), the physician rotates the catheter about the catheter
longitudinal axis until the catheter second end points toward the
desired opening. These catheters require a certain amount of
torque-ability, however, which refers to the extent to which a
catheter transfers a torque in a one-to-one relationship from the
first end to the second end without a whipping effect resulting
from torque build-up in the catheter. Also, as the catheter is
inserted deeper and deeper into a patient, and as the catheter
navigates through a tortuous pathway of vessel openings, catheter
rotation may become more difficult and may present the patient with
some discomfort.
The present inventions solve these and other problems with a
steerable distal second end portion and/or steerable distal tip
that are substantially straight in a relaxed portion and
articulates from a relaxed position to a bending position.
In yet another type of catheter, cables within the catheter help to
maneuver the catheter second end. These cables typically comprise a
wire having a first end attached to the catheter first end, and a
second end attached to the catheter second end. The physician
actuates one or more cables by pulling proximally, pushing
distally, or rotating the one or more cable first ends, which
translates a corresponding movement in the cable second ends and,
as a result, the catheter second end. As is conventional, "distal"
means away from the operator when the device is inserted into a
patient, while "proximal" means closest to or toward the operator
when the device is inserted into a patient. Maneuvering a catheter
with cables requires a catheter having two competing criterion. The
catheter must be sufficiently flexible to avoid damaging the vessel
through which the physician advances the catheter. Conversely, the
cable must have suitable column strength sufficient to allow the
cable to be pushed, pulled, and rotated through the endoscope
channel or a patient's vessel passageway. Moreover, a cable
typically extends through a substantial length of the catheter,
which cable length tends to increase the variable that the catheter
may kink, buckle, bow, or prolapse as a result of the tortuous path
the procedure may require.
The present inventions solve these and other problems with a
steerable distal second end portion and/or steerable distal tip
that have an elastically fluid-distensible occluded distal end
offset from a substantially central longitudinal axis.
Other catheters might consider employing fluid force to steer the
catheter with a fluid actuating lumen that extends the length of
the catheter. One problem they would have with fluid forced
steerable catheters is the tendency to balloon the fluid actuating
lumen as fluid is forced through the actuating lumen to the distal
end. Forcing fluid through the actuating lumen causes the lumen to
expand radially (balloon) along the length of the actuating lumen,
thereby reducing the fluid force in the longitudinal direction such
that there is inadequate fluid force at the distal end to cause the
catheter to bend.
The present inventions solve these and other problems by having a
larger outer diameter (hence, greater thickness to transmit fluid
force) that steps down to a smaller outer diameter at the steerable
distal second end portion and/or steerable distal tip.
Other problems one would have if considering a fluid forced
catheter is radial ballooning of the actuating lumen at the sealed
distal end that is intended to cause the catheter to bend. The
present invention solves these and other problems with an expansion
resistant outer reinforcement.
Also, one considering fluid force for a steerable catheter would,
given the problem with collapsing inward, limit the functionality
of the steerable catheter to steering and possibly a small lumen
for contrast fluid. As a result, their catheters would only be
usable for placing, introducing, exchanging, or replacing
instruments having a central lumen that may pass over the catheter
in a back-loaded or front-loaded medical procedure. Consequently,
the catheters would not be replaceable with a wire guide.
The present invention solves these and other problems with a fluid
forced catheter adapted with a tool receiving passageway disposed
with the catheter and extending to a steerable distal second end
portion. Additionally, the passageway may have a compression
resistant inner reinforcement.
It is therefore desirable to provide an alternative to the
above-described conventional catheters that eliminates or reduces
one or more of the limitations or disadvantages discussed
above.
SUMMARY OF THE INVENTION
The present invention provides steerable catheter devices for use
with endoscopes or percutaneously through vessel passageways and
body cavities. In particular, the present invention provides a
catheter that utilizes fluids to maneuver the flexible second end
portion. Moreover, fluids are especially suitable to percutaneous
and endoscopic surgical procedures because fluids allow for work
over long distances in a flexible arrangement without any
substantive increased in the tendency toward kinking, buckling,
bowing, or prolapse. As taught herein, steerable catheter devices
and methods of articulating catheter devices are provided.
In one embodiment, the device includes a catheter having a first
end portion and a flexible second end portion. A chamber body
extends from a proximal opening at or near the catheter first end
portion to an occluded distal end at or near the catheter flexible
second end portion, and defines a channel therebetween. The
occluded distal end is elastically distensible under an internal
fluid pressure for articulating the catheter flexible second end
portion.
Another embodiment includes a catheter having an elongated
intermediate portion extending from a first end portion to a
flexible second end portion and defining a central longitudinal
axis. The flexible second end portion comprises a steerable distal
tip portion. Two or more elongate chamber bodies are arranged about
the longitudinal axis, with each of the two or more chamber bodies
having a fluid flow channel from a proximal opening located at or
near the first end portion and terminating at a distensible
occluded distal end located at or near the steerable distal tip
portion. A fluid actuator operably connects at or near the first
end portion and is in communication with at least one of the
proximal openings of the fluid flow channels, and is capable of
controlling a supply of fluid to and from the at least one fluid
flow channel. In response to a change in fluid pressure, the
distensible occluded distal end is capable of articulating the
steering tip portion.
Methods of orienting a surgical access catheter device are also
provided. In one embodiment, a method according to the invention
comprises providing a catheter having a first end and a second
flexible end and two or more chamber bodies having a proximal
opening at or near the catheter first end, a distensible occluded
distal end at or near the catheter flexible second end, and
defining a channel therebetween. A fluid actuator capable of
controlling a supply of fluid is provided and connected at or near
the catheter first end in operable communication with at least one
of the proximal openings of at least one of the two or more chamber
bodies. The fluid actuator is operated to control the fluid supply
within the occluded distal end and selectively articulate the shaft
flexible second end in response to a change of fluid pressure
within the occluded distal end.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way
of example, and not by way of limitation, with reference to the
accompanying drawings briefly described as follows:
FIG. 1 provides a perspective view, broken away, and taken in a
distal direction, of a steerable catheter device according to one
embodiment of the invention.
FIG. 2 provides a perspective view, broken away, taken in a
proximal direction, of a steerable catheter device according to
FIG. 1.
FIG. 2A provides a perspective view of a steerable catheter device
having a compression resistant inner reinforcement according to one
embodiment of the invention.
FIG. 2B provides a perspective view of an alternative embodiment of
a compression resistant inner reinforcement for a steerable
catheter device according to the invention.
FIG. 2C provides a perspective view of a steerable catheter device
having an expansion resistant outer reinforcement according to one
embodiment of the invention.
FIG. 3A provides a perspective partial view, broken away, of a
chamber body of a flexible second end portion of an embodiment of
the invention.
FIG. 3B provides a perspective partial view, broken away, of an
alternative embodiment of a chamber body of a flexible second end
portion.
FIG. 3C provides a perspective partial view, broken away, of
another embodiment of a chamber body of a flexible second end
portion.
FIG. 3D provides a perspective partial view, broken away, of still
another embodiment of a chamber body of a flexible second end
portion.
FIG. 4 provides a partial schematic view, broken away, of a
steerable catheter device according to an embodiment of the
invention.
FIGS. 4A through 4G are cross sectional views of FIG. 4 taken along
the lines A-A, B-B, C-C, D-D, E-E, F-F, and G-G, respectively,
according to alternative embodiments of a chamber body of a
flexible second end portion according to the invention.
FIGS. 5A through 5C provide schematic partial views of actuators
for injecting and withdrawing fluids.
FIG. 6 provides a partial schematic perspective view of a second
end portion of a steerable catheter device according to one
embodiment of the invention.
FIG. 7 is a view of FIG. 6 showing the channels and occluded ends
of a steerable catheter device.
FIG. 8 is an alternative partial schematic perspective view of a
second end portion of a steerable catheter device according to one
embodiment of the invention.
FIG. 9 is a partial schematic side view of an alternative
embodiment of a second end portion of a steerable catheter device
according to one embodiment of the invention.
FIG. 10A is a partial schematic side view of an alternative
embodiment of a second end portion of a steerable catheter device
according to one embodiment of the invention shown in a relaxed
position.
FIGS. 10B and 10C illustrate FIG. 10A articulating under an
internal fluid pressure.
FIG. 11 is a block diagram illustrating a method of the
invention.
DESCRIPTION OF EMBODIMENTS
Although not limited in its scope or applicability, the present
inventions relate generally to steerable catheter devices used
percutaneously, through an endoscope working channel, or through an
accessory channel used with an endoscope. More particularly, and by
way of illustration and not by way of limitation, the present
inventions relate to steerable catheter devices comprising one or
more channels having an occluded distal end at or near a flexible
second end portion of the catheter. The occluded distal end
distends axially under an internal fluid pressure, and thereby
deflects and steers the device.
For the purpose of promoting an understanding of the principles of
the invention, the following provides a detailed description of
embodiments of the invention as illustrated by the drawings as well
as the language used herein to describe the aspects of the
invention. The description is not intended to limit the invention
in any manner, but rather serves to enable those skilled in the art
to make and use the invention. As used herein, the terms
comprise(s), include(s), having, has, with, contain(s) and variants
thereof are intended to be open ended transitional phrases, terms,
or words that do not preclude the possibility of additional steps
or structure.
FIG. 1 illustrates a steerable catheter device 10 according to an
embodiment of the present invention. The steerable catheter device
10 comprises a catheter 12 having a proximal first end portion 14
and a flexible distal second end 18, and an elongate intermediate
portion 16.
In describing an embodiment of the invention, the term "catheter"
shall have its plain and ordinary meaning, rather than any
lexicographic definition. Given the configuration of a vessel
passageway or the channel of an endoscope or accessory device, a
variety of catheters 12 of different shapes and sizes can be used
depending on the particular medical applications for the catheter.
For instance, an embodiment of a suitable catheter 12 for a
steerable catheter assembly comprises a tubular member, which may
be better tolerated by the patient to minimize pain and discomfort
than other configurations. The term "tubular" in describing this
embodiment includes any tube-like, cylindrical, elongated,
shaft-like, rounded, oblong, or other elongated longitudinal shaft
extending between a first end 14 portion and a second end portion
18 and defining a substantially central longitudinal axis 11 at the
second end portion 18 and/or at a steering tip portion 22
(discussed below). As used herein and throughout to describe
embodiments of the invention, the "central longitudinal axis" (or
just "longitudinal axis") describes the approximate central
longitudinal lengthwise axis of the catheter's flexible second end
portion 18 and/or steering tip portion 22. The central longitudinal
axis 11 may be straight or may at times even be curved, because as
explained below, the second end portion 18 and steering tip portion
22 are flexible. The first end portion 14 and intermediate portion
16 may also be flexible. Furthermore, the longitudinal axis 11 is
substantially central to the extent that it need not be central to
a mathematical certainty--just approximately central.
Similarly, the dimensions of the catheter will depend on various
factors. These factors include the intended use of the catheter and
the vessel passageway or the channel of an endoscope or accessory
device into which the catheter will be positioned. In general,
however, the catheter is elongate, meaning that it is relatively
long enough to reach a target site at a region internal the
patient's body. The overall catheter length may vary greatly,
however, depending on the intended medical procedure for the device
and the location of the target site internal the patient's body. In
one embodiment, the length of the catheter 12 may be in the range
of between about 50 centimeters ("cm") and about 600 cm, although
the length of the catheter may be shorter or longer as desired.
Alternatively, the length may range from about 100 cm to about 480
cm. For a catheter intended to be used in a common bile duct, one
example of a suitable length may be in the range from approximately
175 to approximately 225 cm.
Just as the catheter length may vary, so, too, the catheter outer
diameter also may vary along the length of the catheter. In one
embodiment, the catheter may have a substantially constant outer
diameter. In another embodiment, the catheter first end portion 14
and/or elongate intermediate portion 16 includes an optional first
outer diameter 15 while the catheter second end portion 18 (or
steering tip portion 22) includes an optional second outer diameter
19 relative to the first outer diameter 15. The second diameter 19
is smaller than the first diameter 15. Optionally, the catheter 12
may generally taper (larger to smaller) from the first end portion
14 to the second end portion 18 and/or steering tip portion 22. In
contrast, the diameter of a catheter 12 need not taper but may
increase at any region or point along the length of the catheter
from the first end portion 14, the intermediate portion 16, and the
second end portion 18. For instance, in one embodiment, the first
outer diameter 15 is substantially uniform (or may comprise a
gradual taper) from the first end portion 14 through the elongate
intermediate portion 16 which then steps down to a smaller second
outer diameter 19 that is located at or near the catheter second
end portion 18 and/or steering tip portion 22. In one embodiment,
by way of illustration only, the first outer diameter 15 may be in
the range from between about 1.0 to about 5.0 millimeters ("mm")
(although the diameter may be lesser or greater than this range),
while the second outer diameter 19 may be in the range from between
about 0.5 mm and about 2.0 mm.
As shown in FIG. 1, the catheter second end portion 18 is flexible.
The second end portion 18 is articulatable (described below) from a
relaxed (e.g., neutral, approximately equal pressure) position 70
to a bending position 80, 90 (e.g., FIGS. 1 and 9). Although the
first end portion 14 also may be flexible, the first end portion 14
typically exhibits less flexibility, or may even be rigid or
semi-rigid, relative to the second end portion 18. Indeed, the
first end portion 14 may be rigid if it extends outside the
patient's body, but flexible where it is to be inserted into the
patient (which includes a patient's vessel passageway; or the
channel of an endoscope or endoscope accessory device to be
inserted into the patient's vessel passageway). Moreover, the
elongate intermediate portion 16 is flexible where it is to be
inserted into the patient so that it may navigate through bends and
turns of the vessel passageway, the endoscope working channel, or
the endoscope accessory channel.
The catheter 12 may be purchased. In the alternative, the catheter
may be made by any methods of extrusion, pultrusion, injection
molding, transfer molding, flow encapsulation, fiber winding on a
mandrel, or lay-up with vacuum bagging, to name a few. A variety of
suitable materials may be used, so long as the flexible sections of
the intermediate portion 16 and the second end portion 18 comprise
materials that allow desired flexibility. For example, suitable
materials include surgical stainless steel or biologically
compatible metals, polymers, plastics, alloys (including
super-elastic alloys), or composite materials that are either
biocompatible or capable of being made biocompatible. The flexible
sections of the intermediate portion 16 and/or the second end
portion 18 may be made of any suitable material (natural,
synthetic, plastic, rubber, metal, or combination thereof) that is
strong yet flexible and resilient comprising, for by way of
illustration and not by way of limitations, elastomeric materials
such as and including any latex, silicone, urethane, thermoplastic
elastomer, nickel titanium alloy, polyether ether-ketone ("PEEK"),
polyimide, polyurethane, cellulose acetate, cellulose nitrate,
silicone, polyethylene terephthalate ("PET"), polyamide, polyester,
polyorthoester, polyanhydride, polyether sulfone, polycarbonate,
polypropylene, high molecular weight polyethylene,
polytetrafluoroethylene ("PTFE"), or mixtures or copolymers
thereof, polylactic acid, polyglycolic acid or copolymers thereof,
polycaprolactone, polyhydroxyalkanoate, polyhydroxy-butyrate
valerate, polyhydroxy-butyrate valerate, or another polymer or
suitable material.
In one embodiment, the flexible second end portion 18, a steering
tip portion 22 (discussed below), and elastically fluid-distensible
occluded distal ends 32, 36, 40, and 44 (discussed below) may
comprise an optional anisotropic material that is, or can be made
to be, relatively compliant in an axial direction as compared to a
transverse direction. This characteristic is known generally as
"anisotropy" (in contrast to "isotropy" where the material
characteristics are uniformly independent of direction or
orientation within the material). In one embodiment of the
invention that uses optional anisotropic material, the specific
anisotropic behavior would be achieved by circumferentially
reinforcing the second end portion 18 and/or steering tip portion
22 so that its "hoop" stiffness (e.g., circumferential stiffness)
is higher than its axial stiffness. This could be accomplished by a
variety of methods, one of which would be to wrap or wind
reinforcing fibers around the second end portion 18 and/or steering
tip portion 22, or to embed them circumferentially within the
material. Consequently, suitable pressurization or depressurization
to elongate chamber bodies 30, 34, 38, 42 would generate forces
within the material that result in desired distention and
articulation, as discussed below.
In the axial direction, the specific type of elastic behavior will
have an impact on articulation, too. If a truly elastomeric
material is used (like a rubber), which by definition has a
distensibility in the range of 200%-800%, then a relatively short
chamber body 30, 34, 38, 42 will be capable of generating a
relatively large angular deflection, resulting in a sharp (short
radius) turn. If a typical substantially non-elastomeric material
is used (e.g., conventional catheter materials) then a relatively
long chamber would be necessary in order to achieve large angular
deflections. The result in that case would be a large-radius bend
at the second end portion 18 and/or steering tip portion 22. Large
angular deflections, however, may not be necessary in order to
cause significant articulation to a catheter device. Deflections of
a few degrees may be all that a physician requires in order to
navigate a catheter to a particular branch a branch, vessel, or
vessel passageway.
For those portions of the catheter 12 that will not contact the
patient (e.g., it is contained within a sheath, working channel of
an endoscope, or an external accessory channel device used with an
endoscope), the catheter 12 material need not be biocompatible. In
contrast, where there is the possibility of patient contact, such
as with the catheter second end portion 18, then the material may
need to be biocompatible or capable of being made biocompatible,
such as by coating, chemical treatment, or the like.
Optionally, a thin PTFE heat shrinkable material coats the catheter
12. The heat shrinkable nature of these materials facilitates
manufacturing while providing a lubricious coating, which
facilitates navigation. The thickness of the coating may vary
between approximately 0.01 mm and approximately 0.20 mm. In another
embodiment, the coating thickness may very between approximately
0.01 mm and approximately 0.05 mm. Alternatively, the coating may
have a thickness between approximately 0.01 mm and approximately
0.02 mm. These thicknesses provide suitable coatings while not
adding significantly to the overall thickness of the device. The
coating may be applied to a substantial portion of the length of
the catheter. In another alternative, the coating may be applied at
least to a substantial portion of the second end portion 18 to be
inserted into the vessel passageway, endoscope working channel, or
an accessory channel used with an endoscope. With or without the
PTFE coating, the catheter or insertion portion of the catheter may
be treated with a hydrophilic coating or hybrid polymer mixture.
Such materials comprise any suitable polyvinyl puroladine and
cellulose esters in organic solvent solutions. These solutions make
the catheter surface particularly lubricious when in contact with
body fluids, which aids in navigation.
Radiopaque materials and markers such as bismuth or gold may be
added to the coating. Also, the second end portion 18 and/or
steering tip portion 22 may further comprise radiopaque materials
and markers, and for instance, by being used with, placed on, or
otherwise embedded in, attached to, or formed into the second end
portion 18 and/or steering tip portion 22. Several examples of
suitable radiopaque materials and markers are known in the art, and
any suitable material and/or marker can be utilized in the present
invention.
One use of an embodiment of the invention may be, by way of example
only and not by way of limitation, endoscopic retrograde
cholangiopancreatography ("ERCP"), which enables the physician to
diagnose problems in the liver, gallbladder, bile ducts, and
pancreas. The liver is a large organ that, among other things,
makes a liquid called bile that helps with digestion. The
gallbladder is a small, pear-shaped organ that stores bile until it
is needed for digestion. The bile ducts are tubes that carry bile
from the liver to the gallbladder and small intestine. These ducts
are sometimes called the biliary tree. The pancreas is a large
gland that produces chemicals that help with digestion and hormones
such as insulin.
ERCP is used primarily to diagnose and treat conditions of the bile
ducts, including gallstones, inflammatory strictures (scars), leaks
(from trauma and surgery), and cancer. ERCP combines the use of x
rays and an endoscope. The endoscope for the ERCP procedure has a
proximal control section remains outside the patient during a
medical procedure and has a distal insert portion comprising a
long, flexible, lighted tube with a means for viewing the inside of
the patient through a viewing lens disposed at the insert portion.
Other common features of an endoscope for ERCP include a working
channel for passing a tool, a light guide cable, and a power
supply.
During the ERCP procedure, the patient will often be positioned on
the patient's side in order to swallow the insert portion of the
endoscope, and the physician will then guide the insert portion
through your esophagus, stomach, and duodenum until it reaches the
spot where the ducts of the biliary tree and pancreas open into the
duodenum. Sometimes the more challenging part of the ERCP procedure
is deep cannulation of the biliary duct. In other words, the
physician needs to move the insert portion of the endoscope through
the main entry of the ducts. Because the network of ducts present
tight passageways that are too small for the insert portion of the
endoscope, the patient may be turned to lie flat on his or her
stomach and a catheter passed through the working channel of the
endoscope. Where the endoscope stops, the catheter may exit the
working channel and then move through the network of the biliary
tree; so that this is not done blindly there may be injection
dye/contrast agents released to the biliary tree. When the catheter
reaches the diseased area, it may be helpful to replace the
catheter with a wire guide for passing other instruments to the
diseased area.
FIGS. 1 and 2 show embodiments of the invention wherein the
catheter has an injection lumen 124 through which dyes and contrast
agents may be injected into the ducts ("a dye injection lumen 124"
or "injection lumen 124"). The injection lumen 124 comprises a
proximal end opening 126 located at the catheter first end portion
14 and a distal end opening 128 located at the catheter second end
portion 18. Through the injection lumen 124, the physician will
inject a dye into the ducts to make them show up clearly on x rays.
X rays are taken as soon as the dye is injected. Using the X rays,
the physician can see the inside of the biliary tree and/or
pancreas so that the physician can guide the catheter inside the
patient toward the target site.
Other catheters might consider employing fluid force to steer the
catheter with a fluid actuating lumen that extends the length of
the catheter, but the problem lies in the catheter having only an
injection lumen. This lumen cannot be used for both injecting the
dyes and as a tool receiving passageway for receiving a wire guide,
by way of example. Indeed, the injection lumen may be too small to
receive the wire guide. In a case where an injection lumen is
configured to receive the wire guide, then the problem is twofold.
First, if the fit is too tight then the injection dye/contrast
agent can no longer pass through the injection lumen. Second, if
the fit is not tight enough, then the injection lumen cannot form a
proper seal at the proximal end of the catheter for the purposes of
forcing dye and contrast fluid to the diseased area. Thus, there
needs to be a separate tool receiving passageway so that the fluid
forced steerable catheter can be replaced by, for instance, a wire
guide to be manipulated through the patient or used as a highway of
sorts for passing other instruments to the diseased area. The
present inventions solve this and other problems with a separate
tool receiving passageway in order to provide additional
functionality to the steerable fluid forced catheter. With the tool
receiving passageway, however, the catheter of a fluid forced
steerable catheter may become unstable and prone to radial
compression. This and other problems are also solved by the present
invention as taught below.
In FIGS. 1 and 2, the first end portion 14 of the catheter 12
comprises an outer circumference 110 relative to the central
longitudinal axis 11. The second end portion 18 of the catheter
comprises an outer circumference (see FIG. 2) relative to the
central longitudinal axis 11. The second end portion 18 of the
catheter comprises an outer circumference 120 (see FIG. 2) relative
to the central longitudinal axis 11, wherein the second end outer
circumference 120 is smaller than (e.g., less than, reduced
dimension, not as large as) the first end outer circumference
110.
FIGS. 1 and 2 further show an embodiment of a catheter 12 having an
optional tool receiving central passageway 24 extending from a
proximal end opening 26 formed at or near the first end portion 14
of the catheter 12 to a distal opening 28 formed at or near the
flexible second end portion 18. The second end opening 28 is
oriented toward a space exterior to the second end portion 18; in
other words, it is at the distal end face of the second end portion
18 (as opposed to the side of the second end portion 18 wherein the
opening 28 is transverse to the central longitudinal axis 11) in
one embodiment of the invention. The distal end face may be planar,
flat, rounded, chamfered, distally tapered, or arrow-head shape
that may be better tolerated by the patient to minimize pain and
discomfort.
Depending on the intended use for the device and the particular
medical procedure to be performed, the passageway 24 of a steerable
catheter may comprise a passageway extending along the longitudinal
axis 11 from the proximal first end opening 26 to the distal second
end opening 28. The term "passageway" in describing these
embodiments of a steerable catheter or steerable catheter assembly
may be any lumen, channel, flow passage, duct, chamber, opening,
bore, orifice, or cavity for the conveyance, regulation, flow, or
movement of or the passage of number of devices for use with the
steerable catheter assembly. For example, these devices may include
diagnostic, monitoring, treatment, operating instruments, tools,
accessories, and therapeutic delivery devices (collectively,
"tools"). One such tool may be a wire guide (also known as a guide
wire). Therefore, the passageway is a tool receiving passageway. In
one embodiment, the tool receiving passageway is a central
passageway, which should be understood to be a passageway
approximately extending along and co-axial with the longitudinal
axis 11 from the second end distal opening 28 to about the first
end proximal opening 24.
The second end opening 28 of the tool receiving central passageway
24 is substantially coaxial with the central longitudinal axis 11
and oriented longitudinally toward a space distally exterior to the
second end portion 18 substantially along the longitudinal axis 11
beyond the end face of the second end portion 18. This is
advantageous for passing a tool (e.g., a wire guide) in a preferred
embodiment wherein the flexible distal second end portion is
substantially straight in the relaxed position. In other words, the
tool may enter or exit without going through any sharp turn as it
must do if the second end opening 28 were on the sidewall (e.g.,
circumference 120) and subjecting the wire guide to kinking,
buckling, prolapsing, recoiling, and the like (collectively,
"kinking"). Indeed, a pre-bent second end portion is easier to
deform once at the target site within the patient, but the
straightened second end portion 18 and/or steering tip portion 22
overcomes problems, such as whipping, that are inherent in the
precurved second end portion in getting the second end portion 18
and/or steering tip portion 22 positioned at the target site.
In one embodiment of the invention, the second end portion 18 of
the catheter may comprise a radial compression resistant inner
reinforcement 130. FIG. 2A provides a perspective view of a second
end portion 18 of a steerable catheter device having a radial
compression resistant inner reinforcement 130 according to one
embodiment of the invention, although it may also represent a
radial compression resistant inner reinforcement 130 of a steerable
tip portion 22 (FIGS. 8 and 9). The radial compression resistant
inner reinforcement 130 is configured to help inhibit radial inward
expansion of a chamber body occluded end (discussed below) caused
by a change in internal pressure of one or more chamber body
occluded ends on the one hand, while allowing stretching, bending,
articulation, and the like of the second end portion 18 and/or
steering tip portion 22 on the other. The radial compression
resistant inner reinforcement 130 is positioned within at least a
portion of the tool receiving passageway 24 at the second end
portion 18 and/or the steering tip portion 22 of the catheter 12.
The radial compression resistant inner reinforcement 130 may be a
layer of or comprise material of a greater durometer (e.g., harder,
more stiff) compared to the distensible occluded distal end, may be
a layer of or comprise an anisotropic material, or may be an
internal spring, coil, mesh, wire, fiber, cannula, or other
equivalent structure that allows the second end portion 18 and/or
the steering tip portion 22 of the catheter 12 to bend while also
resisting inward ballooning when the occluded distal end
experiences a change in internal fluid pressure. By way of
illustration only and not by way of limitation, the radial
compression resistant inner reinforcement 130 may comprise one or a
combination of the following materials: metals and alloys such as
nickel-titanium alloy ("nitinol") or medical grade stainless
steel.
FIG. 2B provides a perspective view of an alternative embodiment of
a radial compression resistant inner reinforcement 130 of a second
end portion 18 for a steerable catheter device according to the
invention, although it may also represent a radial compression
resistant inner reinforcement 130 of a steerable tip portion 22
(FIGS. 8 and 9). In this embodiment, the tool receiving passageway
has been filled with a core section 135. The core section 135 may
be used in the passageway 24 of the second end portion 18 of the
embodiments shown in FIGS. 1 and 2, and may also be used in a
steering tip portion 22. In one embodiment, the passageway 24 is
replaced entirely with the core section 135 for inhibiting radial
inward expansion of a longitudinal fluid flow channel 33, 37, 41,
45 and a an occluded end 32, 26, 40, 44 under a change in internal
pressure of the channels or occluded ends on the one hand, while
allowing stretching, bending, articulation, and the like of the
second end portion 18 and/or steering tip portion 22 on the
other.
The core section 135 may comprise a plug or other filler comprising
any suitable material (natural, synthetic, plastic, rubber, metal,
or combination thereof) that is rigid, strong, and resilient,
although it should be understood that the material may also be
pliable, elastic, and flexible. In one embodiment, the material of
the core section 135 comprises a greater durometer compared to a
distensible occluded distal end. In another embodiment, the core
section 135 comprises a mechanical structure such as a wire or
equivalent structure (natural, synthetic, plastic, rubber, metal,
or combination thereof) that functions substantially the same way
as a wire in the sense that it is flexible while also resisting
inward ballooning of an occluded distal end that a central
passageway or lumen encounter as the occluded distal end is under a
change in internal pressure. The core section 135 may be inserted
into the passageway 24 of the second end portion 18 and/or
steerable tip portion 22, or formed integral into the distal end
portion 18 and/or steerable tip portion 22, during manufacturing.
If formed integral during manufacturing, the core section 135 may
also be advantageous in the sense that it might take less space
than a tool receiving passageway, thereby reducing the size of the
second end portion 18 and/or steering tip portion 22, which is
advantageous in small vessel passageways. Also, the core section
135 may comprise an anisotropic material so that it may stretch
axially and allow the second end portion 18 and/or steering tip
portion 22 to bend. By way of further illustration only and not by
way of limitation, the core section 135 may comprise one or a
combination of the following materials: metals and alloys such as
nickel-titanium alloy ("nitinol") or medical grade stainless
steel.
FIG. 2C provides a perspective view of a second end portion 18 of a
steerable catheter device having a radial expansion resistant outer
reinforcement 140 according to one embodiment of the invention,
although it may also represent a radial compression resistant inner
reinforcement 130 of a steerable tip portion 22 (FIGS. 8 and 9).
The radial expansion resistant outer reinforcement 140 is
configured to help inhibit radial outward expansion of a chamber
body occluded end (discussed below) caused by a change in internal
pressure of one or more chamber body occluded ends on the one hand,
while allowing stretching, bending, articulation, and the like of
the second end portion 18 and/or steering tip portion 22 on the
other. The radial expansion resistant outer reinforcement 140 is
disposed about at least a portion of the second end portion outer
circumference 120 at the second end portion 18 and/or the steering
tip portion 22 of the catheter 12. The radial expansion resistant
outer reinforcement 140 may be a layer of or comprise material of a
greater durometer compared to the distensible occluded distal end,
may be a layer of or comprise an anisotropic material, or may be an
internal spring, coil, mesh, wire, fiber, cannula, or other that
allows the second end portion 18 and/or steering tip portion 22 to
bend while also resisting inward ballooning when the occluded
distal end experiences a change in internal fluid pressure. By way
of illustration only and not by way of limitation, the radial
expansion resistant outer reinforcement 140 may comprise one or a
combination of the following materials: metals and alloys such as
nickel-titanium alloy ("nitinol") or medical grade stainless
steel.
In one embodiment, the radial expansion resistant outer
reinforcement 140 comprises a coil 143. The coil may be compression
fitted or wound around the outer circumference 120 of the distal
end portion 18 and/or steering tip portion 22. The coil 143
includes a plurality of turns, and preferably includes uniform
spacings 143' between the turns of the coil 143. The coil 143 may
be formed of any suitable material that will provide appropriate
structural reinforcement, such as stainless steel flat wire or
biologically compatible metals, polymers, plastics, alloys
(including super-elastic alloys), or composite materials that are
either biocompatible or capable of being made biocompatible. Also,
the coil 143 may be a cannula that has transverse slots relative to
the longitudinal axis of the cannula. The slotted cannula's
transverse slots may be perpendicular to the longitudinal axis of
the cannula or form an acute angle or obtuse angle relative to the
longitudinal axis of the cannula.
Although the embodiment in FIG. 2C shows a flat ribbon shaped wire
coil 143, coils of other cross-sectional dimensions, such as round
wire, may also be used. When flat wire stainless steel is used, the
coil 143 is optionally formed from wire that is about 0.003 inches
thick by about 0.012 inches wide. In one embodiment, the turns of
coil 143 are uniformly spaced 143' apart by approximately 0.0118
inches. While FIG. 2C shows an embodiment that uses coils 143
having uniformly spaced turns and a constant pitch, this is not
required and coils 143 may be spaced 143' by non-uniform distances
or at varying distances. In one embodiment, the ends of coil 143
are positioned approximately 0.197 inches proximal to the end face
of the distal second end portion 18 and/or steering tip portion
22.
FIG. 1 also shows that the steerable catheter 12 comprises at least
one elongate chamber body, such as any one of the chamber bodies
30, 34, 38, 42, respectively. The term chamber and variations
thereof are used to describe embodiments of the invention, rather
than any lexicographic definition regarding those terms. As a
result, a chamber should have its plain and ordinary meaning that
includes any elongated cavity or enclosed volume, space, or
compartment comprising an opening.
Therefore, a catheter according to one embodiment of the present
invention further comprises any one or more of the elongated
chamber bodies 30, 34, 38, and 42. These chamber bodies 30, 34, 38,
42 extend approximately longitudinally from proximal openings 31,
35, 39, 43 at or near the first end portion 14 and terminating at
an elastically fluid-distensible occluded distal ends 32, 36, 40,
44 (hereinafter "distensible occluded distal end(s)" and "occluded
distal end(s)") (e.g., FIG. 7) within the catheter flexible distal
second end portion 18. The occluded distal ends optionally may
comprise an anisotropic material. Occluded distal ends 32, 36, 40,
and 44 are disposed within the catheter flexible second end 18
and/or optional steering tip 22 (discussed below) and are radially
offset relative to the central longitudinal axis 11 of the second
end 18 and optional steering tip 22. The openings 31, 35, 39, 43
and occluded ends 32, 26, 40, 44 define and are in communication
via longitudinal fluid flow channels 33, 37, 41, 45, respectively,
that extend between the respective openings and occluded ends for
allowing changes in internal fluid pressure to transport from the
chamber proximal opening to the occluded distal end.
The distensible occluded distal ends 32, 36, 40, 44 may be any
suitable length at or near the catheter second end portion 18
sufficient, when under positive or negative pressure, to distend
axially (e.g., elongate longitudinally, lengthwise or shorten
longitudinally, lengthwise) and thereby--individually or in
conjunction with another one or more occluded distal ends under
positive or negative pressure--to cause the catheter second end
portion 18 to articulate. In other words, the occluded distal end
32, 36, 40, and 44 elastically distends axially under a change in
internal fluid pressure (described below) and thereby articulates
the catheter flexible second end portion 18 from a relaxed (e.g.,
neutral, substantially equal pressure) position 70 to a bending
position 80, 90 as explained below (e.g., FIGS. 1 and 9). It should
be understood that, where the catheter flexible second end portion
18 comprises a steering tip portion 22 as discussed below,
articulating the catheter flexible second end portion 18 would
articulate the steering tip portion 22, too, or may articulate the
steering tip portion 22 independent of the second end portion
18.
As shown in FIGS. 3A through 3D, the at least one chamber body,
such as 30, 34, 38, 42 for example, may comprise several
configurations. FIG. 3A represents one illustrative embodiment
wherein a distensible occluded distal end 32 is radially offset and
parallel to the catheter 12 central longitudinal axis 11. FIG. 3B
represents an alternative embodiment wherein distensible occluded
distal end 32 is radially offset and substantially parallel to, but
having a bend 32' away from, the catheter 12 central longitudinal
axis 11 near the distensible occluded distal end 32. FIG. 3C
represents an alternative embodiment wherein a distensible occluded
distal end 32 is offset and substantially parallel to, but having a
bend 32' toward, the catheter 12 longitudinal axis 11. In yet
another embodiment, FIG. 3D shows a distensible occluded distal end
32 having more than one bend 32, 32' relative to the central
longitudinal axis 11, and optionally a corkscrew or helical
configuration. Moreover, any one or more the chamber body and/or
corresponding channel may be straight or at times curved, because
the second end portion 18 is flexible while the first end portion
14 and intermediate portion 16 may also be flexible.
In one embodiment, the device comprises a second elongate chamber
body 30, 34, 38, 42 terminating at a second elastically
fluid-distensible occluded distal end 32, 36, 40, 44 radially
offset relative to the central longitudinal axis 11 and radially
offset relative to the first elastically fluid-distensible occluded
distal end 32, 36, 40, 44. In another embodiment, the device
comprises at least a third elongate chamber body 30, 34, 38, 42
terminating at a second elastically fluid-distensible occluded
distal end 32, 36, 40, 44 radially offset relative to the central
longitudinal axis 11 and radially offset relative to the first and
second elastically fluid-distensible occluded distal ends 32, 36,
40, 44.
FIG. 4 schematically shows the catheter flexible second end portion
18 that may have a cross section along the lines A-A, B-B, C-C,
D-D, E-E, F-F, and G-G comprising a variety of suitable
configurations. Any one or more of the at least one chamber body,
such as 30, 34, 38, 42 for example, may comprise several
configurations along any one of the chamber body longitudinal fluid
flow channels 33, 37, 41, 45, respectively. For example, the cross
section may be circular, square, rectangular, triangular, crescent,
semi-circular, oval, elliptical, T-shaped, U-shaped, or otherwise
of a curved configuration.
FIG. 4A, a cross sectional view of FIG. 4 taken along the lines
A-A, includes a circular chamber body channel 33. FIG. 4B, a cross
sectional view of FIG. 4B taken along the lines B-B, includes a
crescent chamber body channel 33. FIG. 4C, a cross sectional view
of FIG. 4 taken along the lines C-C, includes a semi-circular
chamber body channel 33. FIG. 4D, a cross sectional view of FIG. 4
taken along the lines D-D, includes an elliptical or oval chamber
body channel 33. FIG. 4E, a cross sectional view of FIG. 4 taken
along the lines E-E, includes triangular chamber body channels 33.
FIG. 4F, a cross sectional view of FIG. 4 taken along the lines
F-F, includes a rectangular or square chamber body channel 33. FIG.
4G, a cross sectional view of FIG. 4 taken along the lines G-G,
includes a T-shaped chamber body channel 33.
The occluded distal ends are elastically distensible axially under
an internal fluid pressure. The fluid may be any suitable fluid.
Examples of suitable fluids include, but are not limited to, air,
gas, liquid, water, oil, saline solution, or combinations thereof.
In one embodiment, the fluids include liquids or gases that are
biocompatible or capable of being made biocompatible. The occluded
distal ends may comprise any suitable elastomeric material
described above, including by way of illustration and not by way of
limitation elastomeric materials comprising latex, silicone,
urethane, a thermoplastic elastomer, or any combinations
thereof.
As shown in FIGS. 5A, 5B, and 5C, the present invention further
comprises fluid actuators 47. These actuators may comprise any
component for injecting and withdrawing fluids to articulate the
second end portion 18 of a catheter and/or a steering tip portion
22 (as shown in FIGS. 8, 9). For example, the actuators may
comprise mechanically operated elements, electronically operated
elements, electromechanically operated elements, pneumatically
operated elements, hydraulically operated elements,
piezoelectrically operated elements, thermomechanically,
chemomechanically operated elements, and photoelectrically operated
elements.
As one skilled in the art will understand, the actuators 47
illustrated in FIGS. 5A-5C are provide by way of example and not by
way of limitation. According to the present invention, the actuator
47 of FIGS. 5A and 5B depict pneumatic devices. One illustrative
pneumatic device is a syringe having a plunger 49 and a barrel 51
for injecting and withdrawing fluids. Another pneumatic device is
shown in FIG. 5B and comprises a plurality of inflation elements
46, 48, respectively, for injecting and withdrawing fluids, which
inflation elements may include, for instance, a balloon apparatus.
The pneumatic devices of FIGS. 5A and 5B may be remotely,
detachably, and selectively coupled to the first end 14, or
otherwise operatively coupled to be in communication with the
previously described proximal openings 31, 35, 39, 43,
respectively, located at or near the first end 14.
By way of example only and not by way of limitation, the terms
"operatively coupling," "operatively coupled," "coupling,"
"coupled," and variants thereof are not used lexicographically but
instead are used to describe embodiments of the invention having a
point, position, region, section, area, volume, or configuration at
which two or more things are mechanically, chemically, and/or
chemical-mechanically bonded, joined, adjoined, connected,
associated, united, mated, interlocked, conjoined, fastened, held
together, clamped, crimped, friction fit, pinched, press fit tight,
nested, wedged, and/or otherwise associated by a joint, a junction,
a juncture, a seam, a union, a socket, a melt bond, glue,
adhesives, resins, welding (laser, spot, etc.), soldering, brazing,
adhesives, chemical bonding materials, implanted arrangement, or
combinations thereof. The term "communication," and variants
thereof as used herein, includes the passage, conveyance,
injection, ventilation, flow, movement, blockage, withdrawal,
evacuation, or regulation of fluids.
FIG. 5C shows two more embodiments of actuators 47. In the top
portion, the actuator has a control box 50 with first and second
handles 52, 54, respectively, for injecting and withdrawing fluids
through first and second lumens 53, 55, respectively, leading to
any two corresponding proximal openings 31, 35, 39, 43,
respectively. There may be additional handles leading to the other
proximal openings. In the bottom portion, the input/output unit 60
has a plurality of switches 62 that control hydraulic fluids
through a hydraulic cable 64.
The actuators 47 of FIGS. 5A-5C may be used alone or in combination
according to the invention. In all of these embodiments, the
actuator may be located at, within a short distance to, or remotely
positioned relative to the first end 14. Also, these actuators may
attach directly to the openings 31, 35, 39, 43, respectively, or
may operably communicate with the opening via an adaptor 65 that
detachably connects to the openings and/or the first end portion
14. One example of an adaptor 65 may be a Tuohy-Borst or similar
fitting that has one branch with ports in communication with the
proximal openings 31, 35, 39, 43, and has a second branch for the
tool receiving passageway 24. Also, these actuators may be
connected to the openings at the hospital, ambulance, health care
treatment location, or attached during manufacture.
FIG. 6 schematically shows (with x, y, and z axes) the catheter
flexible second end portion 18 that is capable of articulating.
Here, articulate means moveable and includes rotation, bending, or
translational displacements along the x, y, and z axes and
combinations thereof (e.g., between planes formed by the x, y, and
z axes). For instance, the articulation may be axial, longitudinal,
forward, backward, orthogonal, lateral, transverse, rotational,
pivotable, sloping incline or decline, swinging, torsional,
revolving, and other forms of translation and/or rotation in an x,
y, and/or z coordinate system (collectively, "articulation,"
"articulate," "articulatable," "articulatively," and variants
thereof).
FIG. 7 shows a flexible second end portion 18 according to the
invention. The second end portion 18 further comprises a plurality
of longitudinal fluid flow channels 33, 37, 41, 45 providing
passageways for fluids to articulate the flexible second end
portion 18 and/or the steering tip portion 22 as shown in FIGS. 1,
8, 9, and 10. Each channel of the plurality of channels is in
communication with a corresponding distensible occluded distal end
32, 36, 40, 44 (e.g., closed ends of the corresponding chambers)
disposed within the second end portion 18 and/or steering tip
portion 22. The distensible occluded distal end, as used to
describe FIG. 7 and the other embodiments, may be any suitable
dimension and shape, and may be any appropriate width or length
sufficient to distend and, as a result, to articulate the second
end portion 18 and/or steering tip portion 22.
Given the configuration of a vessel passageway to be navigated or
the channel of an endoscope or accessory device, an embodiment of
the catheter flexible second end portion 18 may comprise a flexible
steering tip portion 22. Optionally, the flexible second end
portion 18 has a proximal first outer diameter 19 and the steerable
distal tip portion 22 has a second outer diameter 23 that is
smaller than the first outer diameter 19. The smaller second outer
diameter 23 is configured to minimize pain and discomfort and/or to
reach smaller vessel passageways. Optionally, the steering tip
portion 22 (see (FIGS. 8 and 9) may have a mostly tubular
configuration with a distal tapered, rounded, chamfered, or
arrow-head shape that may be better tolerated by the patient to
minimize pain and discomfort. Further, in certain embodiments, the
steering tip portion 22 may be soft, rounded, and flexible so as to
provide further comfort and safety to the patient.
Depending on the intended use for the device and the particular
medical procedure to be performed, one embodiment of a chamber body
for a steerable catheter assembly comprises a plurality of
longitudinal fluid flow channels 33, 37, 41, 45 arranged about the
aforementioned passageway 24 at the second end portion 18. As used
herein, the term "plurality" has its plain and ordinary meaning of
two or more. Each channel of the plurality of flow channels
comprises a corresponding proximal opening located at or near the
first end portion 14 and a distensible occluded distal end at the
steerable distal tip portion 22, defining a passageway between the
opening and the closed end of the chamber (e.g., the distensible
occluded distal end). The term "each," as used to describe
embodiments of the invention shown in the figures, discussed in
this detailed description, and recited in the claims, simply means
each of the "plurality," which does not foreclose other
possibilities such as, having a flow channel that lacks either an
opening, a distensible occluded distal end, or both, or lacks a
passageway therebetween. The term "about" shall have its plain and
ordinary meaning of describing embodiments of the invention, rather
than defining any claim term. Thus, the flow channel embodiments
may be configured such that the two or more flow channels are
positioned longitudinally around the outside, near but not
necessarily contiguous, of a tool receiving passageway 24, as shown
in FIG. 1.
FIG. 8 shows a longitudinal cross section of an embodiment
comprising a flexible second end portion 18 having a steering tip
portion 22. This embodiment discloses a plurality of channels 33,
41 providing passageways for fluids to articulate the flexible
second end portion 18 and/or the steering tip portion 22. Each
channel of the plurality of channels comprises a corresponding
distensible occluded distal end 32, 40, respectively, located at or
near the second end portion 18.
FIG. 9 is a partial perspective view of a longitudinally sectioned
second end portion 18 and steering tip portion 22 showing
schematically how one embodiment according to the invention works.
FIG. 9 is illustrative only, and it could also represent how a
steering tip portion 22 and/or second end portion 18 articulate.
Moreover, although FIG. 9 shows two distensible occluded distal
ends 32, 40, it could have just one distensible occluded distal end
(e.g., 32 or 40) or could have more than two distensible occluded
distal ends (e.g., 32, 36, 40, 44).
More particularly, where the distensible occluded distal ends 32,
40 are under an approximately equal internal pressure
(P.sub.1=P.sub.2), then the steering tip portion 22 and/or second
end portion 18 assume a relaxed (e.g., neutral or under a
substantially equal pressure) position 70, which is substantially
coaxial with the longitudinal axis 11 such that the length
L.ident.L.sub.1=.sub.2=L.sub.0. The steering tip portion 22 and/or
second end portion 18 may still articulate because it is flexible,
but would do so passively (e.g., by following the curvature of the
vessel passageway).
FIG. 9 further shows that where the distensible occluded distal
ends 32, 40 are under an unequal internal pressure, then the
steering tip portion 22 and/or second end portion 18 will
articulate--by way of example and not by way of limitation--to a
bending position 80, 90. These bending positions 80, 90 are for
illustrative purposes only, as there may be a number of bends 80,
90 along a continuum from the relaxed (e.g., neutral or under a
substantially equal pressure) position 70 to the maximum
articulation allowable by the steering tip portion 22 and/or second
end portion 18. The bending positions 80, 90 may range from
approximately 1 degree to approximately 15 degrees relative to the
neutral position, and in another embodiment from about 2 degrees to
approximately 5 degrees relative to the neutral position, although
the embodiments according to the invention need not achieve the
entire range but simply fall within those ranges, and the bending
positions may be greater if desired.
If P.sub.1<P.sub.2<0 then L.sub.1<L.sub.0<L.sub.2<L
such that the steering tip portion 22 and/or second end portion 18
articulate toward a first bending position 80. Similarly, if
P.sub.1<0<P.sub.2 then L.sub.1<L.sub.0, L<L.sub.2 such
that the steering tip portion 22 and/or second end portion 18
articulate toward a first bending position 80. Conversely, if
P.sub.1>P.sub.2>0 then L.sub.1>L.sub.0>L.sub.2>L
such that the steering tip portion 22 and/or second end portion 18
articulate toward a second bending position 90. Likewise, if
P.sub.1>0>P.sub.2 then L.sub.1>L.sub.0, L>L.sub.2, such
that the steering tip portion 22 and/or second end portion 18
articulate toward a second bending position 90.
In other words, a chamber body longitudinal fluid flow channel 33,
37, 41, 45, as previously described, having a distensible occluded
distal ends 32, 36, 40, 44, respectively, that is under a positive
pressure (in a single chamber embodiment) or greater positive
pressure relative to other distensible occluded distal ends (in an
embodiment having a plurality of chambers) will distend axially
(e.g., will elongate longitudinally in the lengthwise direction)
and, thereby, result in articulation at the steering tip 22 and/or
second end 18. Conversely, a distensible occluded distal end 32,
36, 40, and/or 44 that is under a negative pressure (in a single
chamber embodiment) or greater negative pressure relative to other
distensible occluded distal ends (in an embodiment having a
plurality of chambers) will distend (e.g., shorten longitudinally)
and, thereby, result in articulation at the steering tip 22 and/or
second end 18.
It should be understood that articulation results when one or more
distensible occluded distal ends is under any internal pressure
differential. Thus, one distensible occluded distal end could be
under either a positive or negative internal pressure sufficient to
cause articulation. Also, there could be two or more distensible
occluded distal end under unequal internal pressure (positive,
negative, or positive and negative) sufficient to cause
articulation such that one distensible occluded distal end distends
(elongates longitudinally) and the other distensible occluded
distal end distends (shortens longitudinally).
The steering tip portion 22 may further comprise an expansion
resistant outer reinforcement 140 described above in connection
with FIG. 2B. Likewise, the steering tip portion 22 may comprise a
core section 135 described above in connection with FIG. 2C. In one
embodiment, there is a tool receiving central passageway 24, as
previously described, that is disposed within the catheter 12 and
extends from a first end opening 26 to a second end opening 28, the
passageway 24 being substantially coaxial with the central
longitudinal axis 11 at the catheter flexible steering tip portion
22, wherein the distensible occluded distal ends 32, 40 are
radially offset relative to the passageway 24 and radially offset
relative to each other 32, 40 and other occluded distal ends 36, 44
if present. Alternatively, the passageway 24 may be plugged by a
core section 135, as previously described, in order to provide
reinforcement by uniformly inhibiting radial inward expansion of
the chamber body occluded distal ends 32, 36, 40, 44. Furthermore,
the passageway 24 may comprise a compression resistant inner
reinforcement 130 at or near the steering tip portion 22 and
occluded distal ends 32, 36, 40, 44 as described in connection with
FIG. 2A.
FIG. 10A shows an alternative embodiment of a flexible second end
portion 18 and/or steering tip portion 22 and a flexible
intermediate portion 16 of a steerable catheter device according to
the invention having two distensible occluded distal ends 32, 40.
FIG. 10A depicts two distensible occluded distal ends 32, 40 before
any internal pressure differential, so the flexible second end
portion 18 and/or steering tip portion 22 is in a relaxed (e.g.,
neutral or under a substantially equal pressure) position 70. While
FIG. 10A shows distensible occluded distal ends 32, 40, it should
be understood that FIG. 10A could have one, two, or more
distensible occluded distal ends.
FIG. 10B shows the second end portion 18 and/or steering tip
portion 22 articulating when at least one or more distensible
occluded distal end is under an unequal internal pressure. The
second end portion 18 and/or steering tip portion 22 are shown to
be capable of articulating to a bending position 80 relative to the
neutral position 70. Thus, if the occluded distal end 40 is under
positive pressure, then it will distend (here it is shown
elongating longitudinally relative to the distensible occluded
distal end 32) and the catheter second end portion 18 and/or
steering tip portion 22 articulates to the bending position 80.
This result could also be achieved by creating a negative pressure
in the distensible occluded distal end 32 such that it distends
(e.g., shortens longitudinally relative to the distensible occluded
distal end 40). Additionally, the second end portion 18 and/or
steering tip portion 22 could articulate as a result of a negative
pressure in the distensible occluded distal end 32 and a positive
pressure in the distensible occluded distal end 40.
FIG. 10C shows the second end portion 18 and/or steering tip
portion 22 articulating to the left when at least one or more
distensible occluded distal end is under an unequal internal
pressure. The second end portion 18 and/or steering tip portion 22
are shown to be capable of articulating to a bending position 90
relative to the neutral position 70. Thus, if the occluded distal
end 32 is under positive pressure, then it will distend (here it is
shown elongating longitudinally relative to the distensible
occluded distal end 40) and the catheter second end portion 18
and/or steering tip portion 22 articulates to the bending position
90. This result could also be achieved by creating a negative
pressure in the distensible occluded distal end 40 such that it
distends (e.g., shortens longitudinally relative to the distensible
occluded distal end 32). Additionally, the second end portion 18
and/or steering tip portion 22 could articulate as a result of a
negative pressure in the distensible occluded distal end 40 and a
positive pressure in the distensible occluded distal end 32.
Methods of orienting a surgical access catheter device are also
provided. FIG. 11 shows one embodiment of the method 100 according
to the invention. For example, a method according to the invention
comprises providing (step 101) a catheter having a first end 14, an
elongate intermediate portion 16, and a flexible second end 18
(and/or steering tip 22) defining a central longitudinal axis 11, a
dye injection lumen 124, a tool receiving passageway 24, a
plurality (e.g., two or more) of elongate chamber bodies 30, 34,
38, 42 having a proximal opening 31, 35, 39, 43 at or near the
first end 14 and terminating at an axially distensible occluded
distal end 32, 36, 40, 44, respectively, within the catheter
flexible second end 18 (and/or steering tip 22) and defining a
fluid flow channel 33, 37, 41, 45, respectively, therebetween, the
occluded distal end 32, 36, 40, 44 being radially offset relative
to the central longitudinal axis 11 and being substantially
straight in a relaxed (e.g., neutral and/or relaxed (e.g., neutral,
approximately equal pressure) position 70 and bent to a bending
position 80, 90 under a change in internal fluid pressure.
A fluid actuator 47 capable of controlling a supply of fluid is
provided (step 102) and operably connected (step 103) at or near
the catheter first end in operable communication with at least one
of the proximal openings of at least one of the two or more chamber
bodies. The fluid actuator is operated (step 104) to control the
fluid supply within the occluded distal end, the flexible second
end is selectively articulated (step 105) in response to a change
of fluid pressure within the occluded distal end. It should be
understood in describing the methods according to the invention
that the flexible second end 18 may comprise a steering tip portion
22 containing the occluded distal end that selectively articulates
the steering tip portion 22 in response to a change of fluid
pressure within the occluded distal end. As such, for purposes of
the method claims the second end 18 may be considered a steering
tip portion 22.
In one embodiment, a steering tip portion 22 is provided (step
106). The steering tip portion extends distally from the flexible
second end 18, wherein the intermediate portion 16 has a first
outer diameter 15 and the steering tip portion 22 has a second
outer diameter 19 that is smaller than the first diameter 15.
In one embodiment, a tool receiving passageway 24 is provided (step
108). A wire guide is received (step 110) within the tool receiving
passageway 24.
In another embodiment, a compression resistant inner reinforcement
130, 135 is provided (step 112), the inner reinforcement 130, 135
being positioned within at least a portion of the tool receiving
passageway 24 at the second end portion 18 and/or the steering tip
portion 22 of the catheter 12 and being configured to help inhibit
radial inward expansion of a chamber body occluded end (discussed
below) caused by a change in internal pressure of one or more
chamber body occluded ends on the one hand, while allowing
stretching, bending, articulation, and the like of the second end
portion 18 and/or steering tip portion 22 on the other. Also, an
expansion resistant outer reinforcement 140 may be provided (step
114), the outer reinforcement 140 disposed about at least a portion
of the second end portion outer circumference 120 at the second end
portion 18 (for purposes of the description of the embodiment, the
second end portion 18 may be considered as including the steering
tip portion 22) and being configured to help inhibit radial outward
expansion of a chamber body occluded end caused by a change in
internal pressure of one or more chamber body occluded ends on the
one hand, while allowing stretching, bending, articulation, and the
like of the second end portion 18 and/or steering tip portion 22 on
the other.
The method 100 further comprises a selectively articulating step
wherein fluid is supplied into the chamber body proximal opening
(31, 35, 39, 43), through the fluid flow channel (33, 37, 41, 45),
and into the axially distensible occluded distal end (32, 36, 40,
44). Supplying the fluid to the occluded distal end creates a
positive pressure in the occluded distal end and thereby axially
distends distally the occluded distal end so as to articulate the
catheter flexible second end portion from the relaxed position to
the bending position.
The method 100 further comprises a selectively articulating step
comprises wherein fluid is aspirated from the chamber body proximal
opening (31, 35, 39, 43), the fluid flow channel (33, 37, 41, 45),
and the distensible occluded distal end (32, 36, 40, 44).
Aspirating the fluid from the occluded distal end creates a
negative pressure in the occluded distal end and thereby axially
shortens proximally the occluded distal end so as to articulate the
catheter flexible second end portion from the relaxed position to
the bending position.
A method of orienting a surgical access catheter device does not
need to be performed sequentially. For instance, the fluid actuator
may be provided (step 102) prior to providing a catheter (step
101). Likewise, steps may be combined. For example, a catheter may
be provided (step 101) with a fluid actuator already connected
(step 103) thereto.
It is intended that the foregoing detailed description of the
medical devices be regarded as illustrative rather than limiting,
and that it be understood that it is the following claims,
including all equivalents, that are intended to define the spirit
and scope of this invention. Terms are to be given their reasonable
plain and ordinary meaning. Also, the embodiment of any figure and
features thereof may be combined with the embodiments depicted in
other figures. Other features known in the art and not inconsistent
with the structure and function of the present invention may be
added to the embodiments.
While particular elements, embodiments and applications of the
present invention have been shown and described, it will be
understood, of course, that the invention is not limited thereto
since modifications may be made by those skilled in the art,
particularly in light of the foregoing teachings. Therefore, it is
therefore contemplated by the appended claims to cover such
modifications as incorporate those features which come within the
spirit and scope of the invention.
* * * * *